Hydraulic governor

ABSTRACT

A HYDRAULIC CENTRIFUGALLY OPERATED GOVERNOR WHEREIN A POWER PISTION IS OPERATED ONLY BY OIL PRESSURE IN THE FUEL INCREASING DIRECTION AND ONLY BY RETURN SPRINGS IN THE FUEL DECREASING DIRECTION. A FLOATING LEVER IS ENGAGED WITH THE POWER PISTION AND A SLIDER, CONNECTED TO A LINK, IS ENGAGED TO A MOVABLE FULCRUM OF AN ECCENTRIC SHAFT AND A SPEEDER SPRING IS DISPOSED BETWEEN THE LINK AND FLY WEIGHTS OF THE GOVERNOR. A COMPENSATOR PISTION OPERATIVELY CONNECTED TO THE POWER PISTON INCLUDES TWO EQUAL SPRINGS ACTING ON A PUSH ROD IN A CHAMBER WHICH IS IN COMMUNICATION WITH AN OIL RESERVOIR THROUGH A NEEDLE VALVE, AND ALSO WITH A PILOT VALVE WHICH CONTROLS THE FLOW OF OIL TO THE POWER PISTION CHAMBERS.

1971 NORITOSHI TANAKA 3,609,972

HYDRAULIC GOVERNOR Filed Oct. 13, 1969 3 Sheets-Sheet 1 1971 NORITOSHITANAKA 3,609,972

HYDRAULIC GOVERNOR 3 Sheets-Sheet 2 Filed Oct. 13, 1969 HYDRAULICGOVERNOR 3 Sheets-Sheet 5 Filed Oct. 13, 1969 United States Patent3,609,972 HYDRAULIC GOVERNOR Nontoshl Tanaka, Higashi-Matsuyama-shi,Japan, asslgnor to Diesel Kiki Kabushiki Kaisha Filed Oct. 13, 1969,Ser. No. 865,699 Int. Cl. F151 15/18; F02e 9/04 US. C]. 60-52 SR ClaimsABSTRACT OF THE DISCLOSURE A hydraulic centrifugally operated governorwherein a power piston is operated only by oil pressure in the fuelincreasing direction and only by return springs in the fuel decreasingdirection. A floating lever is engaged with the power piston and aslider, connected to a link, is engaged to a movable fulcrum of aneccentric shaft and a speeder spring is disposed between the link andfly weights of the governor. A compensator piston operatively connectedto the power piston includes two equal springs acting on a push rod in achamber which is in communication with an oil reservoir through a needlevalve, and also with a pilot valve which controls the flow of oil to thepower piston chambers.

The present invention relates to and has for its object to provide ahydraulic governor which is attached to a row-type fuel injection pump,which governor has a very high range of controlling characteristics, anextremely wide range of regulation and is suitable for use in all dieselengines.

In order that the present invention may be more readily understood,reference will now be made, by way of example, to the accompanyingdrawings, in which:

FIG. 1 is a schematic diagram of a hydraulic governor in transversesection according to the present invention.

FIG. 2a is a detailed perspective view of a speed regulation andfluctuation rate mechanism and FIG. 2b is a simplified diagram thereof.

FIG. 3 is a detailed perspective view of a compensator mechanism.

Referring now to FIG. 1, the governor according to the invention isdirectly attached to a fuel injection pump 1, actuated by a cam shaft 2to which is fixed a speed acceleration gear 3 adapted to rotate a pilotvalve bushing 4 having ports 4a, 4b, and 4c at the speed of accelerationgear 3. To one end of said pilot valve bushing 4, there is connected agear shaft 6 of a gear pump 5 which serves to deliver oil at workingpressure from a source to the hydraulic governor and on the other arefly weights 7 for detecting the speed of rotation of the governor,respectively, these being rotated at the same speed of rotation as thepilot valve bushing 4. In the pilot valve bushing 4 is provided a pilotvalve 8 movable in the axial direction by the centrifugal force of thefly weights 7 and by said pilot valve 8 to control the working oilbetween the gear pump 5 and a power piston 9 controlling the fuelinjection pump 1. The fly weights 7 engage the pilot valve 8 through athrust bearing and a speeder spring 10 is afforded a preset loadopposite to the centrifugal force corresponding to the speed of rotationof the fly weights. The pilot valve 8 is provided such that a valveportion 8a of the pilot valve 8 may close the port 4b of the pilot valvebushing 4 when the speed of rotation of the engine is in a balancedcondition, and thus the fly weights 7 and the speeder spring 10 arebalanced in force, but with an increase in the load on the engine andthe resultant decrease in the speed of rotation of the bushing 4 thecentrifugal force of the fly weights 7 is less than the load of thespeeder spring 10 so that the pilot valve 8 shifts to the right from theposition shown in FIG. 1 and both ports 4a and 4b are connected to eachother. The working 3,609,972 Patented Oct. 5, 1971 oil from the gearpump 5 flows into a cylinder in which the power piston 9 operates andmoves the power piston 9 to the right side from the position shown inFIG. 1, that 1s, in the increasing direction of fuel feed. Inverselywhen the load on the engine is reduced the centrifugal force of the flyweights 7 increases so that the pilot valve 8 moves to the left sidefrom the position shown in FIG. 1 and the ports 41; and 4c are connectedto each other so that flow of the working oil in the rod end of thepower piston cylinder will be directed into a governor oil reservoirsince the power piston 9, by the force of two strong and weak returnsprings 11 and 12, respectively, on the opposite sides of said piston,is moved to the left from the position shown on the drawings, that is,in a decreasing direction of fuel feed. In other words, the governor ofthe present invention operates the power piston 9 by oil pressure onlyin the increasing direction of fuel feed and the operation in the fueldecreasing direction is carried out by the two return springs 11 and 12.Then, between the gear pump 5 and the pilot valve 8, there is provided acheck valve 13 and an accumulator 14 for maintaining a constantpressure. The accumulator 14 consists of a movable piston and a springand serves to maintain the constant pressure of the working oil and atthe same time makes up the deficiency of feeding capacity of the workingoil of the gear pump 5 upon a sudden variation of load. The forward endof a rod of said power piston 9 is provided with a pin 15. On thefulcrum of a movable pivot 16a of eccentric shaft 16, there is provideda floating lever 18 having long grooves at one end engaged to the pin 15and at the other end engaged with a slider 17 sliding in the interior.To this slider 17 is connected :1 link 19 having a pin 19a. The otherend 19b of the link 19 is connected to a fork link 20 which rotatesabout a control lever shaft 20a. The eccentric shaft 16 may be providedwith a scale device 21. The fork link 20 is provided with a controllever 22. Between the two fulcrums of the link 19 is connected thespeeder spring 10 through the spring fork 23 carried on a pivot 190.

The operation of this mechanism will now be explained. Hereinafter,reference to the direction of movement of elements, such as to the rightor left will be understood to be with respect to FIG. 1 of the drawings.The speed adjustment of the governor is made by operation of the controllever 22, whereby the speeder spring 10 is deflected correspondingly. Asits load is varied the engine speed is varied accordingly. When thecontrol lever 22 is fixed and the speed of rotation of the engine isreduced under a predetermined load, the power piston 9 is transferred inthe decreasing direction of fuel feed that is, to the left side forstopping the rise of the speed of rotation of the engine. Movement ofthe power piston 9 rotates the floating lever 18 about a movable fulcrum16a of the eccentric shaft 16 and the slider 17 at the lower part of thefloating lever 18 moves to the right side. As the lower fulcrum 19b ofthe link 19 is fixed the fulcrum also moves to the right side and thespeeder spring 10 is deflected and provided with a new preset load. Bythis increased set load the power piston moves to the left side by anincrease of the centrifugal force of the fly weights 7 and this pushesthe pilot valve 8 to a position at which the ports 4a and 4c areconnected to move again to positions to the closing of the port 4b,balancing with the centrifugal force of the fly weights 7 at a speed ofrotation slightly above the initial balanced condition thereby settingit as this speed of rotation. By this link mechanism it is possible toobtain the fluctuation ratio of speed. Inversely when the load on theengine is increased the movement of the power piston 9 in the increasingdirection of fuel feed extends the speeder spring 10. In consequence,adjustment 3 is made at a position corresponding to a slightly lowerspeed than that in the balanced condition at the initial rotation speed.Assume that speed of rotation in the balanced condition is N and thespeed of adjusted rotation iS N1.

6 in the above formula will be determined by the lever ratio of theabove described link mechanism. If, as shown in FIG. 2b, displacement ofthe power piston 9 is given as x; amount of deflection of the speederspring 10 as y; and distances between the link fulcrums, the pin 15, themovable fulcrum 16a, the pin 1901, the lower fulcrum 19b, and thefulcrum 19c, as l l l and respectively, the following formula will beobtained:

in which it is noted that y is large so long as e is large. This formulashows that as the pilot valve 8 rapidly closes the port 4b by a largedisplacement of y the balance of the engine load and the engine outputis obtained at a value much higher or lower than in the case where N hassmaller y. Herein, as 1 and 1 are constant, y is determined by l l (l +lconstant) which is determined by rotation of the eccentric shaft 16.Thus, when the movable fulcrum 16a of the eccentric shaft 16 and the pin19a of the link 19 are in agreement 1 As the movement of the pilot valve8 through the speeder spring by y is not restricted the pilot valvecompletely follows the variation of speeds of rotation, therefore, 2 canbe made zero.

On a connecting part 24a of a connecting rod 24 extending to the rightend of the power piston 9 and the control rack of the fuel injectionpump 1, there is provided another link 25, which moves on a movablefulcrum 26a of an eccentric shaft 26, wherein the movement of the powerpiston 9 is transmitted to a push rod 27 for operating the compensatormechanism. This movement of the push rod 27 is transmitted throughresiliency of springs 28 to a compensator piston 29 provided in themiddle of said two equal springs 28 so that the chamber on the left sideof piston 29 pressurizes or expands and the oil in the chamber is led toa chamber at the right end of the pilot valve 8 and to a needle valve 30and further through the needle valve 30 to the governor oil reservoir.The eccentric shaft 26 may be provided with a scale device 31.Accordingly, when the speed of input rotation of the governor rises thepower piston 9 moves in the decreasing direction of fuel feed so thatthe link 25 rotates counterclockwise at the fulcrum 26a and thecompensator piston 29 moves to the right by the force of the spring 28.Therefore, the volume of the chamber to the left of piston 29 increasesand oil flows from the governor oil reservoir through the needle valve30. When the flowing oil is throttled by the needle valve 30 there isgenerated a negative pressure in the chamber, which actuates the pilotvalve 8 to the right side or opposite to the centrifugal force of thefly weights 7 so as to temporarily close the once opened port. Therebyit is possible to delay somewhat the action of the power piston 9relative to the variation of input or the responsiveness thereof.Inversely when the speed of input rotation is lowered the piston 29 ispushed by the push rod 27 through the spring 28 so that positivepressure is generated to similarly delay the responsiveness. This actionserves to prevent the sudden variations of the speed in rotation of theengine caused from a sudden variation of an engine load and ingeneration of hunting to obtain a stable performance.

As hereinbefore described, the present governor has two feedbackelements in use as a speed regulation ratio mechanism and a compensatormechanism, the effects of which mechanisms can be widely and simplyadiusted fluctuation ratio of speed c:

4 from outside of the governor by the eccentric shafts 16 and 26 and theneedle valve 30.

Besides, the governor of the invention, when it is attached to the fuelinjection pump 1 for equipment in the engine, has a drag spring 32 forcompression in the power piston 9 to adjust the change of position ofthe fuel rack as required for the output and purpose of the engine, towhich spring is connected a control rack of the pump 1 through theconnecting rod 24, and a stopper 37 for stopping the control rack at apredetermined position on the side opposite to the governor of the pump,whereby the position of the full rack can be simply adjusted in whatengine it may be used.

Other characteristics of the present governor lie in that the operationin the decreasing direction of fuel feed is made by means of two returnsprings 11 and 12 so that there is provided a valve for letting thepressurized oil in the cylinder escape effecting the simple stoppage ofan engine in whatever position the control lever may be set. Thisprinciple is incorporated in a stopping shaft 33 which operates a rotaryvalve, to the outer end of which shaft 33 is attached a stop lever 34.The lever 34 may be turned in (or less) by which action the cylinderhaving the power piston 9 and the oil reservoir of the governor arepassed through a valve to release the pressurized oil of the cylinder sothat the control rack is moved back to a zero position and the engine isstopped. This mechanism is an engine stopping device to be manuallyoperated. In addition, it is possible to equip an electromagnetic valveor a piston 35 and an electromagnet 36 as shown in FIG. 1 and stop theengine by remote control.

As the centrifugal force of the fly weights 7 of the present governor issmall and the speeder spring 10 is weak so that it is possible to makethe reactionary force of the control lever 22 very small, said lever 22is operated by a small motor to remote control speed setting of theengine.

As described above, the governor of the present invention has highcontrolling characteristics, is extremely wide in the range ofadjustment and is an all speed governor with which it is possible toremotely control the engine so that it is suitable for all kinds ofengines for general industrial use in ship building, electric generationand the like and construction use and the other general objects.

Many variations may be effected without departing from the spirit of thepresent invention. It is to be understood that these, together withother variations in details, are encompassed within the appended claims.

I claim:

1. A hydraulic governor comprising: a power piston for controlling afuel feed pump, a pilot valve bushing which is rotatable about its axis,fly weights operatively connected to the pilot valve bushing to moveoutwardly in response to an increase in the speed of rotation of thepilot valve bushing, shaft means for operatively connecting the pilotvalve bushing to a gear pump to operate the pump by rotation of thepilot valve bushing, a pilot valve slidable axially within the pilotvalve bushing, said pilot valve being operatively connected to the flyweights to undergo said axial sliding movement in one direction inresponse to the application of centrifugal force to the fly Weights, anda speeder spring for urging the fly weights to their retracted positionsand hence causing the pilot valve to move in the opposite direction, apassageway between the gear pump and the power piston, said passagewaybeing controlled by the axial position of the pilot valve, said powerpiston being movable in the fuel feed increasing direction only underthe influence of pressurized liquid and movable to the fuel feeddecreasing direction under the influence of spring means, and a controlmeans for regulating the operation of the power piston in response tochanges in the speed and the fluctuation rate of speed, said controlmeans comprising: a floating lever having one end engaged to one end ofsaid power piston and at its other end said floating lever beingconnected to one end of a slider which slider is connected to a link atits other end, said floating lever being mounted to turn about avariable fulcrum of an eccentric shaft, said link being in connectionwith a fork link which is in turn connected to a control lever, and saidspeeder spring connected to the link and extending therefrom to the saidfly weights.

2. A hydraulic governor according to claim 1, comprising a further linkconnected to an end of the power piston and an end of a control rack ofthe fuel feed pump, said further link being carried on a variablefulcrum of an eccentric shaft and positioned to operate a push rod, acompensator piston mounted to be acted on by the push rod in a chamberhousing and including two springs of equal strength located one on eachside of said compensator piston, said push rod and said chamber being influid communication with an oil reservoir through a needle valve andalso with the side of the pilot valve at which a pressure build-up wouldoffset the force of the speeder spring.

3. A hydraulic governor according to claim 1 including a drag springoperatively mounted within the power piston and tending to urge the saidpower piston to the fuel decreasing position relative to the means whichconnects the power piston to the fuel feed pump.

4. A hydraulic governor according to claim 1 including a means forstopping the engine by releasing pressurized oil from the power piston,thus permitting the said spring means to urge the power piston withoutthe resistance of pressurized fluid to the fuel feed decreasing positionuntil the engine stops.

5. A hydraulic governor according to claim 2, including a drag springoperatively mounted within the power piston and tending to urge the saidpower piston to the fuel decreasing position relative to the means whichconnects the power piston to the fuel feed pump, and including a meansfor stopping the engine by releasing pressurized oil from the powerpiston, thus permitting the said spring means to urge the power pistonwithout the resistance of pressurized fluid to the fuel feed decreasingposition until the engine stops.

References Cited UNITED STATES PATENTS 2,324,516 7/1943 Kalin 91-366 X2,602,654 7/1952 Parker 91-366 X 3,148,501 9/1964 Oldenburger 91-366 X3,412,648 11/1968 Newburgh 91-366 EDGAR W. GEOGHEGAN, Primary ExaminerUS. Cl. X.R.

